C.,
I pretty much went through the same thing when I started menopause. I had my period for 9 straight weeks, and it was so bad that I actually passed out twice. The doctor tried me on hormones as well, but it didnt help, and also made my breasts very sore. Also I was not a good candidate for the hormones because of a history of breast cancer in many members of my family.
Have they tried doing a D&C on your sister? That may stop the bleeding, although it didn't work with me. 3 days later I just started in with the bleeding again, and my doctor just didn't seem to be taking it very seriously.
When I passed out the second time, my regular gynocologist was on vacation, and his associate treated me. Since I didn't plan to have any more children, he decided to do a partial hysterectomy, and removed my uterus. He was able to remove it vaginally, rather than by making an incision, or by laparoscopy. I was back at work in only two weeks, and felt 100 percent better!
If your sister doesn't plan to have any more children, then that may be the way to go. If her own doctor doesn't seem to be taking this seriously, then I would suggest that she go to another doctor, and seek a second opinion. Constantly bleeding is no fun, and if it goes on long enough, can be a very real threat to your general health, causing anemia and many other health problems.
If I were you, I would insist that she seek a second opinion, even if you have to go with her to make sure that she does! If she can find a doctor willing to remove her uterus, she will feel 100 per cent better within two weeks. Having mine removed was the best decision I ever made!
D.